Two cycle internal combustion engines carry their lubricant in the fuel itself. The use of two cycle engines is increasing due to high power to weight requirements on such things as motorcycles, chain saws, power boats and the like.
A problem of two cycle engines is encountered in the fact that excess lubricant which is unburned causes pollution, but if an excess of lubricant is not present, the result may be a shortfall of lubricant which causes engine failure.
Also, the user of the two cycle engine typically mixes the lubricant into the fuel. Thus, mistakes are often made with respect to proper fuel mixtures, resulting in either a shortfall of lubricant which can destroy the engine, or an excess of lubricant which is undesirable in terms of pollution and undesirable smoke generation. Also, the two cycle engine lubricant generally comes at the present time in inconvenient, small cans in an attempt to overcome the difficulties that users have in mixing the fuel.
By this invention an improved lubricant is provided which may be mixed in lower concentrations with engine fuel than conventional two-cycle oil, while effectively providing lubrication, with a resulting reduction of both cost and undesirable pollution. Additionally, the lubricant of this invention may be a solid material until it is added to the fuel, which facilitates its addition by the simple counting of lubricant tablets to be added to a given amount of fuel. This also permits packaging of the lubricant in a less expensive form.
In Schuettenberg et al. U.S. Pat. Nos. 4,515,740 and 4,639,255, various fuel additives such as detergents are proposed for addition to engine fuel in pellet form. However, there is no teaching of the addition of a lubricant of any sort in pellet form. Similarly, Morway et al. U.S. Pat. No. 3,114,708 teaches dry blends made from polyolefins and oil, which blends are useful as lubricants and lubricant thickeners. Such a blend is a grease-like material. Most greases of the prior art comprise a fluid lubricant plus a filler to provide a solid material.
By this invention, a solid lubricant composition is provided which is particularly useable as an additive to two cycle engine fuel. Certain embodiments of the lubricant composition of this invention may be provided to the fuel in the form of a liquid or a solid tablet, so that it is easily measured into the fuel in desired concentration by dropping a specified number of tablets into a particular volume of fuel. Also, the preferred lubricant of this invention can be added to gasoline in lower concentrations than conventional lubricating oil, while the resulting fuel can still be successfully used in two-cycle engines. For example, preferred lubricants of this invention may be mixed with gasoline at ratios of 100:1 to 300:1 while still providing successful lubrication to the gasoline for use in two-cycle engines. Because of this, less fuel dilution occurs. Less waste, and lower smoke exhaust is also achieved.